Semipalmated sandpipers (Calidris pusilla) get their name from the small webs between the toes. They are “peeps,” the common slang for the five smallest sandpipers (least, Baird’s, Western, and white-rumped sandpapers are the other four). They most resemble the least sandpipers, but have black legs rather than yellow legs.
Semipalmated sandpiper, Jamaica Bay Wildlife Refuge, May 27, 2020
Semipalmated sandpiper on takeoff, Jamaica Bay Wildlife Refuge, May 31, 2021